As requirements for data storage density increase for magnetic media, cell size decreases. A commensurate decrease in the size of a writer is difficult because, in many systems, a strong write field gradient is needed to shift the polarity of cells on a magnetized medium. As a result, writing data to smaller cells on the magnetized medium using the relatively larger write pole may affect the polarization of adjacent cells (e.g., overwriting the adjacent cells). One technique for adapting the magnetic medium to utilize smaller cells while preventing adjacent data from being overwritten during a write operation is interlaced magnetic recording (IMR).
IMR utilizes alternating data tracks of different written track widths arranged with slightly overlapping edges so that a center-to-center distance between directly adjacent tracks (e.g., the track pitch) is uniform across the surface of the magnetic medium. In some heat-assisted magnetic recording applications, tracks of different write widths are created by varying laser power. However, prolonged usage of a laser at high power levels can significantly shorten the functional lifetime of a laser. In some perpendicular magnetic recording applications, variable track widths are created by two writers of different size on a same transducer head. However, manufacturing processes for multi-writer heads is inherently more complex than manufacturing processes for single-writer transducer heads.